Kamen Rider Kiba:
Komori Kiba, the Shy Hero. However, by using Coumorin, he can change his character into split personalities, and fight against the FanGire using secret magical powers. His weapons: The Monster Arms, stored at his inheritance, the CastleDran. Garuru, the werewolf. Shamaid, the gillman. And GoranStein, the Frankenstein's Monster. Their souls stay with and protect him, becoming his weapons and having some control over him as well.
Kamen Rider Blow (previously known as Hunter):
Ataru Souga, user of the Kitami-Ken, obtains the ShouKen Fighter Arm and transforms. Souga, only uses power, and has no weapons of his own. By chance, he obtains his own Fessels and can summon the same weapons as Kiba. He attacks Kiba, vying for the title of "Savior".
The FanGire (VanKire):
A race of vampiric creatures who attach themselves to people for the purpose of sucking their energy and gaining strength. Their purpose is to revive their King with the energy they collect. The only way to remove a FanGire from a person, is by the use of a Fessel. Once removed, the FanGire can be fought with. A human bearing a FanGire will be marked with the "Σ" symbol